Leardriver

My Feedback: (12)

Well I went flying last Wednesday and had a less than desirable day. I took off with my 3.3M Comp-Arf Yak, did one trim pass and pulled up into a loop....the plane plane barely pulled out and narrowly missed the ground. It felt very mushy on elevator and I thought perhaps the gears on the servos had stripped. I was able to land the plane uneventfully with one elevator working....you could see the other was not working as I flew downwind but was able to land uneventfully.

Once I got to the plane the elevator was not functioning...there was no power to the two servos that controlled the elevator half, but about two minutes after I landed it looked like the servos were "trying" to move but still no power and it was very easy to move the elevator by hand without any resistance. Now comes the part that made me go nuts........the thing just sprang back to life and we could NOT reproduce the problem no matter what we did!!! ARG!

Ok and quick rundown on the equipment that was installed. I have two Futaba 149DP RX going into a Duralite PowerBox Pro fed by two 4000mah Duralite lithium packs. There are 13 JR 8611s throughout the plane with a total of four on the elevators. Also each stab was equip with a Smart-Fly equalizer to match the servos in each stab.

My first inclination was to suspect the equalizer on the left half, so I pulled both out and ran another extension and used to free PMIXs in my 9Z and the two open ports on the powerbox and setup the elevators with the matching devices (like I should have from the beginning). I was pretty confident that the problem layed with the the equalizers. Well, when I was sitting behind the plane checking to make sure eveything was set on without binding the elevator AND rudder failed. I was pissed to say the least! Ok, now it can only be the Powerbox, an extension, or a receiver. Now I couldn't gdt it to doit again! Just perfect!

As luck would have it I decided to leave the plane on when I went in to get a another RX to try, when I came back the stab and rudder had failed...didn't work at all! I quickly unplugged them and switched them to to the other rx and they worked! I than plugged in the "new" RX I brought out and all functioned properly. Next I plugged in the original rx ad nothing! Whoohoo! At least I know what failed!

Now that brings me to my next point......dual receivers! If there was not two receivers installed in the plane it would have been destroyed!! Period...there is no doubt about it. I had one functioning elevator because I had one functioning receiver! And the argument about doubling the the chance for failure is just BS because that second receiver would have gone into my Super Extra and functioned perfectly for 60 flights before going intermittent and failing. It simply would have destroyed the next plane it was installed in. It even range checked perfectly before the flight. By the way this was a brand new unit when installed in the Yak!

Bottom line I will never have a giant scale plane without two recievers! I have always subscribed to the practice last week it payed dividends!

Leardriver

Swat Cop

My Feedback: (11)

Yep. I agree 100%. Recently since some of the big names like Somenzini ect fly with one RX the trend has been to follow them. The argument that there are twice as many points to fail may be true but if one does fail atleast you have a back up system to get the plane to the ground safely. They chance of two separate RX systems failing at the same time is highly remote.

captinjohn

I am glad you saved your plane. Why don,t the maker of this RC stuff....make a reciever that is 2 built into one, with a place to power it by 2 seperate batteries? Kinda like stero? Thanks Capt,n

kenzo

Hi,

Are there any helps, FAQs, instructions on installing twin receivers? I am getting worried. Thanks

jsm77777

My Feedback: (4)

Glad you saved your plane. I have ALWAYS used dual receivers/batteries/switches in all my 40% sized planes over the past 8 years. I will never switch. People have told me a single receiver is fine, and "less" complicated. Your situation proves the point of the dual receiver set up as being ideal. It doesn't matter to me what the team JR guys are doing, or other sponsored pilots. The dual receiver set up works, lessens the load on the receivers, gives more power to the servo's, and it doesn't need other expensive fixes like the powerbox. Scott

jsm77777

My Feedback: (4)

In reply to KENZO, just divide the airplane in half, and run one side off of on Rx, and the other side on the other. Use 2 batteries and switches with one set for each side. Keep the receivers apart around 4 inches or so, although I have had them as close as 2 inches with no problems. Then set up the plane as you normally would do if you were using 1 Rx, like the aux channels for ailerons, and elevators. Once you do this, you will find it's reliable, and really very simple. Scott

Gremlin Castle

My Feedback: (14)

It is interesting to find another thread talking about intermittant failure of R-149 DPs. I had a variation of the same thing happen to me but the plane was still on the ground getting ready for the 2nd flight.
I sent the receivers back to Futaba and they could not duplicate the failure.
After watching them do the same thing on the bench several more times, I have scheduled mine for the local landfill.[]
As much as it pains me I won't risk another multi thousand airplane to a $150 receiver that apparently no one can fix reliably.
I bought 3 of them at one time and two of the three have failed in the same manner.
For the time being I am going back to the old R-129 DPs since I have 20+ on hand.

JohnVH

My Feedback: (38)

There ya go, $150 saved you $8000+! I run twin RX's in my 3.3m as well. Cheap insurance. But still only one in my jets

Diablo-RCU

My Feedback: (1)

Another idea might be to avoid a receiver (149DP) that is proving to be unreliable.
I'd rather have one good receiver than two that have a high probability for failure.
Maybe the price of the 129 receivers will go up like a fine wine.

OnTheEdge

Glad, you saved your plane Paul! I 'd like to fly it again some day




..........Mark

P.S. The new field is up and going. You'll have to do a road trip some weekend and stop by with the Yak (see smart-a$s comment above ) Perfect field for giant scale.

matus777

Dumb question about dual RCVR'S but why divide the plane into rt side-lt side? Would it not be better to cross the contols....ie.....rt ail...lt elev & rud (rcvr #1) then perhaps lt ail...rt elev & throttle (rcvr #2)?

OnTheEdge

That's the way I do it. Cross everything up. Throttle servo on one Rx and the choke servo or electronic ignition kill on the other Rx.

Leardriver

My Feedback: (12)

"Glad, you saved your plane Paul! I 'd like to fly it again some day!"



I bet you do! Yea it really upset me when I couldn't find the problem and there was no way I was gonna attempt to fly it before I was sure I had found the problem.

I heard about the field..I figure it's a good 2 hrs from me but I'll get out there in the near future.


Oh yea, this is the first 149DP to give me any kind of problem...so we'll see.


Leardriver

jsm77777

My Feedback: (4)

Doesn't matter whether you divide the plane in half, or criss-cross the controls. Either way gives you the redundancy needed. I don't criss-cross the controls, just divide in half and hook it up. Scott

Swat Cop

My Feedback: (11)

I criss cross my controls also.

going vert

My Feedback: (11)

Glad you saved it.

I also run 2 RXs, but the throttle plugs into one RX only. So, if I lose that RX I lose throttle. Is that how you do it?

Also, I've been told to run a male to male between the 2 RXs. That way if one RX fails the other will operate the servos through the male to male. I don't do this, but it makes sense. Anyone have experience with this setup?

Leardriver

My Feedback: (12)

I don't think that plugging a male to male extension in between two receivers will allow you to maintain control of the servos plugged into it, but it would allow a receiver to continue to function in the event of a failed switch or battery as it should run on the other one powering the second receiver. In my case I am running a Duralite Powerbox so a failed battery or switch will not effect the function of either of my receivers.

Oh yea, I do plug the throttle servo directly into one receiver. I have considered running an "engine kill" on the other one but to this point have not.

Leardriver

jtemple42000

I run dual rxs and batteries as well. here is a pic of the set-up.

Swat Cop

My Feedback: (11)

Looks very similar to mine. I am running dual Hitec Q-PCM receivers, dual JR switches, (2) Fromeco 4800 mah with regulators for the recievers and a 2400 mah Fromeco with regulator for the ignition on my 40% Cap.

Swat Cop

My Feedback: (11)

Damn those pics came out big. Thats like one to one scale.[X(]

TT2

My Feedback: (13)

Yeah, thank God I'm not on dial-up! Click for fullsize? I'd have to buy another 21" monitor! heehee

-Tom

sillyness

My Feedback: (25)

I plug a choke servo into the second RX... easier starting, easy to kill motor, and less chance (as compared to a fiber-optic kill switch)of motor quitting due to a quick radio glitch. For the record, I have used the fiber kill in the past.

I'm going to try a male-male jumper with a 7 Amp fuse... should prevent draining both batts with a short.

Leardriver

My Feedback: (12)

Hey Sillyness a buddy of mine does that...put a jumper with a fuse between the two receivers, but I am not sure if I would go 7amp. I think he went to a 2amp fuse so if the load became too much the fuse would blow quicker and isolate the remaining rx. But overall i think if your not going the powerbox route it's a pretty good idea.

Leardriver